Fluid-pressure-operated device



April 5, 1927. 1,623,780

c. 'r. cRocKl-:R

FLUID PRESSURE OPERATED DEVICE.l

Filed Nov. 17, 1921 2 Sheets-Sneekl l O O O O O O f f/"f' .Ya-f my ef/fsw -v Z6 Tr inventor". Clarence T. CT'OCHQT;

April '5' 1927'. c. r. cRocKER FLUID PRESSURE OPERATED DEVICE 2 She'ets-Sheet 2 Filed Nov; 17. 1921 EXHAUST HPESS UFE -f/YHAUST EXHAUST PRESS UAE EXHAUST* EXHAUST PRESSURE Inventor: Clarence 'I'.Cr'oc Ker',

PRESSURE* Hs'flttor'neg.

20 matic motor,

Patented Ape-'5, 1927-:

UNITE D. STAT-Es ,l f 1,623,780 PATENT. OFFICE.

MENGE T. CBOCKEBLOF SCHENECTADY,VNEW YORK, ASSIGNOB 'IO-GENERAL' HEC- TRIO COMPANY, A CORPORATION 0F NEW YORK.

` ILUm-PBESSURE-OPERATED DEVICE.

Application mea November 17, 1921.I serial No. 515,996.Y

able device is positively operated to and exactly'stopped at a predetermined position or positions.

m. VOne of the diiiiculties experienced in the operation of devices of the above character' is that of getting the device to stop exactly at a desired predeterminedposition because c of the fact that the fluidpressurem'otor. is apt to overshoot; that is, run a short distance beyond the desired stoppingpoint.v Thus, for instance, in a controller o erated each way from-a predeterminedposltion to other definite' ositions by a reverslble pneuiiculty is experiencedil returning thecontroller from either portion of the definite positions exactly to the middle, predetermined position.

In carrying my invention into efect in a controller operated each way from apr-edetermined position to'other definite,"positionsby a pneumatic motor, I provide a second or auxihary pneumatic motor cooperatingwith means-for exactly determining the stopping I 30 position of the motor, for example a mechanical stop for operating the controller to the desired predetermined position after operation to other positionsby the main 'pneumatic motor. be designed for the single purpose of obtaining an accurate stop for the controller. v Thus, the auxiliary pneumatic motor has two pistons operatively connected to the controller and having relative movement with res ect thereto. When. the controller is moveA by the main pneumatic motor in either direction from the predetermined mid-position to a definite position, one of the pistonsof the auxiliary pneumatic motor is also moved, so that when pneumatic pressure is released from the main motor and applied to the `auxiliary motor, `this piston of the auxiliary motor will operate the controller to th predetermined. mid-position; Themtherpiston of the auxiliary motor is pressed againstV a stop by the gas under pressure and serves to arrest the controller exactly at the mid-position.

For a better understanding of my invention, reference is had tothe accompanying,

This auxiliary pneumatic'motor mayy drawings wherein I have'shown an embodiment of the invention in a multi-position pneumatically operated controller of the character described above for the pur ose of explaining the principles thereof. Reerring to the drawings, Fig. 1 is a side view of a pneumatic motor operated electric controller, Fig. v2 is a sectional view of the pneumatic motors shown in Fi 1 taken on the section line 2-2, looking 1n the direction of the arrows, and Figs. 3, 4 and 5fare dia ammat'ic lillustra-tions of the relative posltions' of the several operative parts of the pneumatic motors during different' phases of operation. p

Referring first to Figs. 1 and 2, the controller operatedby the pneumatic motors comprises the shaft 10 to which cams 11, 12 and 13 are secured for operating switch mechanism (not shown). The shaft 10 is operated by means of the main pneumatic motor .14. This motor is controlled by meansof the electromagneticyalves 15 and `lwhich respectively control passages leading from a source of gas under pressure and also passagesleading to the exhaust. These passages are .not shown in detail for the reason that they are not of the essence of my invention. .The second or auxiliary -`pneumatic motor 17 is provided for operating the 4controller exactly to its predeter"y mined mid-position. This second or auxiliary motor 17, in the. preferred lform shown in the drawing', is reversible and comprises a cylinder and: a pair of trunk pistons 25 and 27 which reciprocate-- respectively between the right and left hand ends of the cylinder and a central stop 28. A rack 26, of substantially the same length as stop 28, isslidably supported between the mechanically independent reciprocating'pistons 25 and 27 in engagement with a pinion .23 `keyed on the end of the controller shaft (not'shown) and also exhaust passages (not shown).

' By reference to Fig. 2, it will be observed that the pneumatic motor 14 is provided with two pistons 20 and 21 connected toa rack 22 which is` connected Lto a pinion 23 on the end ofthe shaft of the controller. When gas under pressure is' admittedV to the right-hand end of the pneumatic motor 14 by `the operation of the electromagnetic valve 15 and the left-hand end of the cyl- /inderof the neumatic motor is connected to atmosphere y the operation of the electromagnetic valve 16, the piston willmove the rack 22 toward the left until the piston 20 comes into engagement-with the. .stop 24. The pinion 23 and the shaft 10 are lthereby rotated counterclockwise from the predetermined mid-position (that shown in Fig. 2) to a definite osition as shown in V 'F ig. 3. A certain re ation of the circuits controlled by the controller'is thereby established. When the pinion 23 is thus moved counter-clockwise, both ends of 'the cylinder of auxiliary pneumatic motor 17 are connected to atmosphere by operation of electromagneticgvalves 18 and 19 and the piston "acribed, is shown diagrammatically in Fig.

3, aswell as the relative positions which the electromagnetic valves f15, 16, 18 and 19 occupy durmg this operation. lf now the electromagnetic valves 15 and 16 should be operated to respectively exhaustv the gas under pressure in the right-hand end of the cylinder of the main motor 14 and admit gas under pressure to the left hand of this cylinder, it will be evident that vthe piston 21 of the main motor will return the rack 22 towards the right and rotate the pinion 23 and shafty 10 in a clockwise direction. This operation may beh continued until the piston 21'comes into engagement with stop 29 and it will be understood thatby pro erly operating either valve 16 'to exhaust t e gas under pressure from the left hand end or valve 15 to admit gas underY pressure to the right hand end it is possible to stop the movement of rack 22 when the pinion 23 and ,shaft 10 has reached .the predetermined mid position shpwn in Fig. 2. But as pointed out above, considerable diculty may be experienced in getting the rack 22 to stop movement with the controller shaft 10 exythe mam motor.

actly in the predetermined position by operation .of either electromagneti'valve 15 or 16. as just described. Alf however, after operation to the position shown in Fig. 3, the gas under pressure should be exhausted from the right-hand end of the cylinder of the main motor 14 by the operation of the electromagnetic valvej 15, and gas under pressure be admitted to both ends of the auxiliary motor by the operation of the electromagnetic valves 18 and 19, lthe piston 27 will be forced against the left-hand end of the stop 28, and the piston 25 will move the rack 26 to the left until this piston also comes into engagement with the right-hand so end of the stop 28. The pinion 23 will Vthereby be 'rotated in the clockwise direction to return the controller to the exact predetermined' mid-position shown in Fig. 2. The relative positions of the racks, pistons es and electromagnetic valves of the two motors at the termination of this phase o operation is'shown in Fig. 4. The controller will be returned exactly to the predetermined position because of the fact that the piston 27 will serve as a stop for the rack 26, and the piston 25 will be arrestedv at the exact mid-position. Over-shooting i of the controller beyond the mid-position is thereby prevented.

When it is desiredfto rotate the controller shaft clockwise from the predetermined mid-position to a denite position, gas under pressure is admitted to the left-hand end of the main motor 14 by the operation of the 10P electromagnetic valve 16, the electromagnetc valve 15 maintaining the connection to exhaust for the right-hand end of the cylinder of the 'main inotor. The piston 21 will thereby operate the rack 22 to the right V5 until this piston comes into engagement with the stop 24. The pinion 23 will slide the rack 26 of the auxiliary motor to the left, carrying with it thepiston 27, the pist0n 25 meanwhile remaining stationary U0 against the right hand end of stop 28. Fig.

5 shows therelative position of the several parts uK on completion of this operation of In order to return the controller exactly to the mid-position, both 5 ends ofthe cylinder of the main motor 14 Vare connected to exhaust by the electromagnetic valves 15 and 16, and gas under pressure' is admitted to bothends of the auxiliary motor by the operation of the valves 320 18 and 19. rllhe piston 27 now serves to slide the rack 26 to the right, thereb ro-f tating the pinion 23 .and the sha t 10 counter-clockwiseto the exact mid-position,v

the piston 25 of the auxiliary motor in this 1.25'

case serving as the stop for arrelsting the tendency of the auxiliary motor to overshoot. f

In accordance with the provisions of thev u patent statutes, I havedescribed the prin ciple of operation of my invention, together ing the said device to different positions with the apparatus which I now consider to represent the best embodiment thereof, but I desire to have it understoodthat the apparatus shown is only illustrative and that the invention maybe carried out by other means.

WhatfI claim as new and desire to secure by Letters Patent of the United States, is

1. The combination with a device o c rable to a plurality of positions, or a uld pressure motor for operating the same from an intermediate one of said positions to any selected one of the remaining positions and `a second fluid pressure motor having a plurality of separately o erable pistons, each for operating the sai device from a different direction to said intermediate pos1- tion. v

2. The combination with a device o erable to a plurality of positions', of a uid pressure motor for operating the same each way from a predetermined position to other definite positions, and a second fiuid pressure motor having a pair of separately operable pistons, each for operating 'the said device from a corresponding portion of the said definite positions to the said predetermined position.

3. The combination with a device operable to a plurality of positions, of a reversible fiuid pressure motor for operating the same from a predetermined one of said positions to any selected one of the remainin positions, a mechanical stop, and a secon reversible fluid pressure motor cooperatin with said mechanical stop for returnin an 'stopping the device exactly at said pre etermined positions.

4.,.,The combination with.. a device oper-- able to a plurality of positions, `of a reversible fluid pressure motor for operating the same each way from a predetermined position, a mechanical stop, and a second reversible fluid pressure motor comprising a Y pair of mechanically independent pistons cooperating with said mechanical stop for returning and stopping the device exactly at thesaid predetermined position.

5. The combination with a device operable to a plurality of positions, of a plurality of mechanical stops, a plurality of reversible fiuid pressure motors mechanically connected to the device and each cooperating with a different one of said mechanical stops for selectively operating and stopping the controller at different predetermined positions.

6. The combination with a device .operable to a plurality of positions, of a. plurality of mechanical stops. a plurality of reversible fluid pressure motors for operatdetermined by said stops, and electromagnetically actuated valves for admittmg pressure to one motor and exhausting pres- 7. The combination with a controller v having a shaft, of a pneumatic motor havin a piston directly connected to the sai shaft for operating the same each way from a predetermined position to other definite positions, and a second pneumatic motor having a plurality of pistons operatively connected to the said shaft, one of said pistons serving as a stop for the shaft and the other of which returns the said shaft to the said predetermined position.

8. The combination with a controller having a shaft,.of a pneumatic motor having a pluralit of pistons directly connected to the said s aft, one of said pistons for operating the said shaft in one direction from a predetermined position to a definite position and the other of said pistons for operating the shaft in the other direction to another` definite position, and a second pneumatic motor having a pluralit of plstons operatively connected to. the said shaft and relatively movable with respect thereto, the said pistons being arranged so` that one is moved with the said shaft depending on the definite position Ato whichthe shaft is moved and then returns the shaft to the redetermined position, the other piston o the second pneumatic motor then serving as a stop for arresting the mot-ion of the shaft at the said predetermined position.

9..TheA combination with a controller having a shaft for operating switch mechanism, ya pinion /on the sha t, a pneumatic motor having a rack coo erating with the said pinion for rotating the shaft each way from a redetermined intermediate position to a de nite position, pistons connected to ends of the said rack for operating the said shaft to the said definite ositions, a stop for limiting the travelof t e pistons at the 'said definite positions, a second pneumatic motor having a second rack operatively connected to the said pinion and a piston cooperating with each end of the second rack motor serves as a stop for the said second rack.

In witness whereof, I have hereunto-set my hand this 16th day of November,1921.

CLARENCEA Tf. CROCKER. 

